When I was a kid, I packed a book in my lunchbox every day: always science-fiction or fantasy. To this day when I smell bananas I think of spaceships. I’d get so wrapped up in a book I’d read it not just on the bus, but walking along the street to the bus, like people do now with phones. I got through so many sci-fi books that one day I found I’d read the library dry. I just went back and started re-reading them all.

Recently, I found a purpose for all this useless knowledge: the Guardian commissioned me to write a series of articles about Dune, for the Folio Society’s special 50th anniversary edition. I hadn’t just read the book five times as a kid – I’d won a Mastermind-style contest at prep school with Dune as my special subject. So writing the intro piece, about how Frank Herbert had initially been rejected by 23 publishers, was a blast.

I also had to compile and review 25 top works of sci-fi and fantasy. I found I had read all but two of them (and with those I had seen the films), which simplified research somewhat. Nice to have my misspent youth coming in handy.

But my favourite piece was an idea I had, that they weren’t sure about until I wrote it: a travel guide to Dune, written as though for the discerning intergalactic traveller of the future.